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Biofuels/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Moby and Tim are behind the counter of a fast-food restaurant. Tim closes out his cash register. TIM: Alright, Moby. It's quitting time. Let's close up quick so we can get home in time for Dancing with the Stars. MOBY: Beep. Moby walks to the deep-fat fryer and drinks the grease from it through a tube. TIM: Aargh! What are you doing? Moby hands Tim a typed letter, which he reads. TIM: Dear Tim and Moby, What is biofuel, and how is it used? Sincerely, Linus. Biofuel is any source of energy that's made from biomass, or material derived from living organisms. An image shows a plant leaf. TIM: Biofuels can be made from things like plants and vegetable oils, but also other stuff like animal manure, algae, and even cooking grease. Images illustrate what Tim describes. MOBY: Beep. TIM: No, fossil fuels like coal and oil don't count. Biofuels are made from recently living organisms, and they're much better for the environment. For one thing, they're renewable. An image shows a field of sunflowers. TIM: All the fossil fuels on Earth will eventually run out someday, but we can always grow new plants. Secondly, they're designed to be carbon-neutral. An animation shows a gushing oil well, which gradually stops flowing. TIM: When we burn fossil fuels, we release lots of carbon-based gases into the atmosphere. That's bad for the planet, since these gases contribute to pollution and global climate change. An animation shows smoke pouring out of the tailpipes of cars and factories, polluting the air. TIM: The plants used for biofuel, on the other hand, actually remove carbon dioxide from the atmosphere as they grow, through photosynthesis. This offsets, or makes up for, the carbon emitted when the fuel is burned. Oh, and biofuels tend to burn cleaner and emit less carbon than fossil fuels, too. An image shows a cornfield with the sun shining down upon it. Arrows show carbon dioxide being removed from the atmosphere and oxygen being released. MOBY: Beep. TIM: Well, today the most common type of biofuel is ethanol, or ethyl alcohol. That's the same stuff used in alcoholic drinks. It's usually derived from corn and sugar cane, but it can be made from other crops, too. An image shows a gas pump labeled ethanol. A split image behind the pump shows corn and sugar cane. TIM: Ethanol is made through a process called fermentation. Basically, tiny microbes absorb the natural starches and sugars in plants and produce alcohol as a byproduct. Two cartoon bacteria lie on their backs, eating sugar and burping. TIM: The alcohol is then purified and mixed with gasoline. One common blend is called E10. That's ten percent ethanol, ninety percent gas. It can be used in regular gasoline-powered cars. Meanwhile, blends that contain up to eighty-five percent ethanol can power special flex-fuel automobiles. An image shows a car at a gas pump being filled with E85ethanol. MOBY: Beep. TIM: Right. Well, first of all, ethanol isn't as efficient as gasoline. You can't drive as far on a single tank, and you have to fill up more often. An animation shows two cars starting off at the same time. One is powered by ethanol, and one by gas. The car with the ethanol stops running and the other car keeps going. TIM: Also, growing and harvesting the crops requires energy, much of which still comes from fossil fuels. That means ethanol isn't quite as environmentally friendly as it may seem. An animation shows a combine processing grain. TIM: Using existing farmland to make biofuel can also lead to temporary food shortages and price hikes. The alternative is to convert wilderness areas into farmland, but that's bad for the environment, too. An animation shows the price of corn rising in a supermarket. MOBY: Beep. TIM: You're right, Moby. Ethanol's not the only biofuel. Biodiesel requires less energy to manufacture than ethanol. It's usually made out of vegetable oils, like sunflower and soybean oil. But it can be made from animal fats and waste grease from restaurants, too. Images show a flask of biodiesel fuel, and the substances it is made from that Tim describes. TIM: Biodiesel can be used in anything that takes normal diesel fuel, like trucks and other heavy vehicles. Burning biodiesel emits less than half as much greenhouse gas as regular diesel fuel, which comes from oil. But biodiesel has its problems, too. An image shows a farmer filling his pickup truck with biodiesel fuel from a pump. TIM: Producing all that vegetable oil still requires a lot of farmland. Plus, the fuel turns solid at low temperatures. And it's not as efficient as regular diesel, either. An image shows various fields of crops. MOBY: Beep. TIM: Glad you asked. TIM: Right now, scientists are working on a new generation of biofuels that are more efficient and environmentally friendly. An animation shows two scientists doing research in a lab. TIM: One example is cellulosic ethanol, which is based on the cellulose contained in the cell wall of green plants. An image shows a beaker half-filled with green liquid. A second image shows the cellular structure of a corn plant. TIM: This kind of fuel can be produced from parts of crops that can't be eaten, like stems, stalks, leaves, and husks. Animations illustrate the parts of a plant. TIM: Or you can make it out of wild grasses and even wood chips and fruit pulp. Since every green plant on Earth contains cellulose, producing this stuff doesn't require a lot of farmland. Images show wild grass and wood chips. TIM: Another promising technology involves algae, the plantlike organisms that can be found in virtually all the world's waterways. Algae grow where most plants can't, and produce hundreds of times more fuel per square kilometer than ordinary crops. An animation shows a shallow body of water overgrown with algae. TIM: Algae can also grow up to thirty times faster than ordinary crops, so it can be harvested many times a year. An animation shows algae growing underwater. MOBY: Beep. TIM: Well, as I said, these technologies aren't ready yet. But if they're perfected, the new fuels will be good for the environment and will help countries all over the world achieve energy security. That means that instead of importing oil from foreign countries, they'll be able to grow their own fuel right at home. Side by side images shows an oil rig and two people looking at a corn plant. TIM: Anyway, it's almost time for Dancing with the Stars. You ready to go? Moby is sucking grease from the grease trap through a tube. He swallows it and burps. He cringes and covers his mouth. In the end, Moby shook his head no. 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